Solar Panels 101: The Basics For Solar Panels & Mobile Living
Buying and installing solar panels for camper vans and/or RVs is a great way to become energy independent and enjoy traveling off-grid. One of the greatest aspects of “van life” is being able to get out and enjoy nature BUT ALSO to be able to stay out there for an extended period of time without having to worry about electricity issues.
That’s why we think installing solar panels for your camper van conversion is 100% the right decision for most people dreaming of their own van life adventure. But before rushing to purchase any random solar system kit for your campervan, it’s important to understand the basics of solar panels.
Warning: This article is long! In this article, we will discuss everything you need to know to about solar panels for camper vans. In this post, we will talk about:
- Are solar panels necessary for a camper van?
- Which solar panels we recommend for camper vans
- How many solar panels you need
- Attaching solar panels to your camper van’s roof
- How to incorporate solar panels to your camper van’s electrical system
- And recommend solar accessories
Consider this article your “Camper Van Solar Panel 101” course.
Not What You Want? Go Back: Campervan Electrical System Installation Guide
Table of Contents:
Solar Panels For Camper Vans: Are They Necessary?
This is a common question we hear and one that we even asked ourselves when we first planned our DIY van conversion.
“Do I REALLY need solar panels for my camper van?”
In most cases, we believe that installing solar panels on your camper van is a great way to bring clean and consistent electricity into your camper van.
The Pros Of Installing Solar Panels
If you plan for solar panels in your DIY van conversion, you’ll able to:
1. Live Off-Grid
We love boondocking out in nature with our camper van. But once batteries reach 0%, camping becomes more inconvenient. With solar panels on your camper van, you’ll be able to recharge your batteries while out in nature, allowing you to keep doing what you love to do for longer.
2. Save Money In The long Run
Having camper van solar panels also saves you money in the long run by not having to constantly stay at expensive RV parks so that you can plug into shore power. RV parks cost around $30 per night and can be much more expensive for nicer parks. Having solar panels on our van conversion allows us to skip these expensive RV parks.
3. Learn A Thing (Or Two!) About Solar Electricity
We were interested in installing a camper van solar system because we also wanted to learn about renewable energy and how to incorporate solar energy in our van conversion. If you’re also interested to learn a thing, or two, about how to harness clean energy, keep reading this article! We will discuss how to install and wire solar panels on a camper van.
1. Costs Add Up Quickly
With the combination of solar panels, the charge controller, the wires, and several other accessories, the total cost adds up quick. Our solar installation costs almost $800. Even a smaller, starter set will set you back ~$300.
2. Installation = Holes In Your Roof
Whether you decide to install your solar panels directly on your roof or on a roof rack, you will likely need to drill holes through your vehicles roof. This means increased chance for water leaks when it rains and rust formation.
3. Reduces Your Stealth
One of the dead giveaways as to whether a vehicle is a campervan or just a normal commercial van is by looking at the van’s roof. If you know what you are looking for (aka police & thieves), solar panels are pretty obvious looking, especially when looking at the van from above. However, even if you’re concerned about stealth, we don’t believe building a 100% stealth campervan is advisable.
Are Solar Panels Right For You?
We think installing solar panels on a campervan is the right choice for most people in the van life community.
However, there are several situations where having solar panels to charge your batteries isn’t necessary.
1. The Weekend Warrior: If you’re building a campervan just to get out for the weekends, chances are that you can simply charge your batteries before you leave and charge them again when you get back home.
2. The Constant Driver: If you don’t fancy settling down for long periods of time in one spot and tend to always be on the move, you could simply connect your campervan’s batteries to your vehicle’s alternator and charge your batteries while you drive.
But if you don’t feel that the above two scenarios fit your situation, then solar panels may be for you. If you think so, too, then keep reading!
How Many Solar Panels Does Your Camper Van Need?
If you have decided that installing solar panels is for you and that you have already sized your battery bank, it’s time to determine what size “solar array” your campervan requires.
Solar Panel vs Solar Array
Very intuitively, a “solar panel” is a single panel made up of multiple solar cells. A solar panel (measured in watts) can vary in size, but for mobile homes, a 100w panel is the most standard. (Although we use 175watt panels).
A “solar array” is a collection of solar panels wired together to generate more electricity. So if you have two 100 watt solar panels wired together, you’d have a 200 watt solar array. Since we use two 175 watt panels, our solar array is 350 watts.
How To Determine Your Solar Array Size
Keeping it simple, we believe you should have AT LEAST 100 watts of solar for every 100Ah of batteries you have.
In our campervan, we have 300Ah of lithium-ion batteries and 350 watts of solar panels on our roof.
Even with multiple days of sun-less days, our panels can bring in enough electricity on sunny days to erase our energy deficit from the days before.
Note: You should NOT determine the size of your solar array by your estimated energy usage. Your estimated energy usage should dictate the size of your battery bank. The size of your battery bank should dictate the size of your solar array.
Overestimating Your Solar Panel Needs Is Good
Attempting to estimate your daily energy intake from your solar array is tricky because the amount of sun your panels will be exposed to will differ each day. And therefore the amount of power that goes back into your batteries will differ.
- Did you park in the shade?
- Does your camp spot happen to be under a tree?
- Is extended cloudy days in the forecast?
- Is it the rainy season?
Even the shade of a single tiny branch that covers less than 10% of your solar panels will significantly reduce the rate at which these panels harvest power from the sun. It can be frustrating.
Figure 1: Our Solar Power Intake Data
In the above graph, we show our daily solar power intake over 19 days. You can see that our daily intake can vary wildly depending on where we park.
Though we tend to average about 650 watt-hours per day, in reality, we can produce as much as 1.4 KWh and as little as 150Wh per day. Each day is different.
Therefore, if your budget allows, we really recommend overestimating your solar panel needs. Even an extra 100 watt panel can make a huge difference in the solar sustainability of your campervan electrical system.
Solar Panel Options For Camper Vans: Rigid vs. Flexible vs. Suitcase Solar Panels
Solar panels for camper vans and RVs come in different shapes, sizes, and constructions. And each solar panel type has their advantages and disadvantages, especially when pertaining to camper van life. Here we discuss the pros & cons of rigid, flexible, and suitcase-style solar panels.
Rigid Solar Panels For Camper Vans
Rigid solar panels get their name because the solar cells are contained within a rigid aluminum frame and mounted under tempered glass. When you’re outside and you see solar panels mounted on buildings, these are typically rigid solar panels.
Great Durability (Best For Camper Vans)
Because of the tempered glass and strong frame, rigid solar panels are more durable for outdoor use. They can better withstand physical abuse from both the environment and humans; this includes brush-ups with low-handing branches, sand & dust storms, hail, and when cleaning these panels.
Due to their stronger and more durable frame, rigid solar panels typically last longer than flexible panels (10+ years vs ~3 years). rigid panels are also about 20% cheaper than flexible panels.
Pros of Rigid Solar Panels:
Cons of Rigid Solar Panels:
In fact, we chose rigid solar panels for our camper van conversion. We’ve been on the road for 2+ years already and our rigid panels have, so far, withstood the test of time. We love them!
Flexible Solar Panels For Camper Vans
As their name suggests, flexible solar panels are…flexible! This means that these conveniently thin panels can bend and warp to better contour to their mounting surface.
Thin & Light! (Stealthy Option For Camper Vans)
Flexible panels are also much lighter than their rigid panel counterparts. Watt-for-watt, flexible panels are about 70% lighter than rigid solar panels.
And because of their uniquely thin profiles (0.10”), these flexible panels are more ideal for complete stealth camping. These thin flexible panels, when mounted on a camper van’s roof, are much harder to see from the roadside.
But the largest drawback of flexible solar panels is their plastic construction. Although great for flexibility, these panels are more prone to wear and tear than rigid solar panels. Not only does their plastic top-layer scratch easier than a rigid panel’s tempered glass, but the solar cells wear out faster because they cannot dissipate heat as well as rigid solar panels.
Pros of Flexible Panels:
Cons of Flexible Panels:
In our experience, roughly 25% of all the camper vans we’ve seen use flexible solar panels. We prefer rigid solar panels for our camper van, but understand that every body’s situation is different. Check below to see one of the best flexible solar panels on the market today.
Suitcase Solar Panels For Camper Vans
If fixing solar panels on your camper van roof does not appeal to you, solar panel suitcases can be a great alternative. When needed, these solar panels can be taken out, placed on the ground and set up in the sun. And when you’re ready to hit the road, simply fold panels up and conveniently store them inside your van.
No installation necessary, these solar panel suitcases are perfect for stealth camping. And because the panels can be moved around, you can always position the panels directly facing the sun for maximum energy efficiency.
Convenience At A Cost...
The largest downside is that because these suitcases are stored inside, solar electricity production is not constant. Some of our largest electricity production times are when we’re driving or parked in public places where it would be inconvenient to set up a solar panel suitcase.
Because of this reason, we feel the other solar panels, which are mounted on the roof are better for long-term campervan living.
Pros of Suitcase Panels:
Cons of Suitcase Panels:
In our 2+ years living in our camper van, we’ve come across a total of three vans that utilize solar panel suitcases to charge their batteries. Though they acknowledge the inconveniences of these types of solar panels, they also appreciate the stealth aspect of their panels. Check below for the best suitcase solar panels on Amazon.
Our Recommended Solar Panels For Camper Vans
We installed two 175-watt solar panels from Newpowa. What can we say other than that they work great! Through snow storms, Mexico’s torrential rainy season, and continuous beat downs from low hanging branches, these panels have performed well for the 2+ years (and counting) that we’ve been on the road.
Another reason we love these solar panels for our van conversion is that the width of two of these panels, when side-by-side, fits perfectly on the roof of our camper van for maximum space efficiency. If you have a Ford Transit, Mercedes sprinter, or Dodge Promaster, consider purchasing a pair of these 180-watt panels.
Learn more about these panels on their Amazon page. The 175-watt versions are no longer available, but are replaced with an 180-watt upgraded panel with exactly the same dimensions as ours.
All-In-One Solar System Kits
Putting together your own camper van solar system, piece by piece, is a rewarding process and allows you to get exactly what you want out of your system. But for those with neither the time, budget, nor the inclination, convenient solar system kits allow you to get everything you need in just a single purchase.
These all-in-one solar system kits often include:
- Solar Panels
- Solar Charge Controller
- Mounting Brackets
- Appropriate Cables
If you’re based in the USA, we recommend Renogy’s solar all-in-one kits. Convenient, great quality, and solid customer service.
Recommended Solar Accessories
Solar Charge Controller
A solar system essential. Solar charge controllers control the amount of power (voltage & amps) that is put into your batteries. When a battery is charging and gets close to 100%, a solar charge controller reduces the power being sent to the batteries. Without a charge controller, you risk over charging and damaging your batteries.
A charge controller is like your brain when you’re eating. When you’re full, your brain tells you to stop eating. Overeating can have serious bodily consequences, no? 🙂
We love our Victron 100/30 charge controller. It comes Bluetooth enabled so we can view all our solar stats on our smartphone with the Victron App, which makes staying on top of our solar energy situation much more convenient.
Wires & Accessories
A few other accessories will be required for your solar installation build. We list the most important ones below.
How To Install Solar Panels On A Camper Van Roof
How to install solar panels on a camper van is one of the most important parts of a van conversion’s solar system build. Sure, you could simply just screw the panels straight into the van’s sheet metal roof, but with a bit more planning we can do much better than that.
We wanted to achieve two things when attaching our rigid solar panels to our camper van roof.
1. Create A (Very) Strong Bond Between Solar Panel & Camper Van Roof
Simply drilling screws into the razor thin sheet metal roof did not give us confidence of a strong hold. We would be experiencing strong headwinds when driving our camper van and we needed some extra reinforcement.
2. Minimize Risk of Water Leaks
Installing two solar panels meant drilling a total of 16 holes through our camper van’s roof. This would create 16 weak points for water to leak in and wreck havoc inside. We needed to make water-tight, robust seals around each drill hole.
What You Need To Install Solar Panels To Your Camper Van's Roof
Ordinarily, you would first attach the Z-brackets to the rigid solar panels and then screw the Z-brackets to the van’s roof. However, in order to create a strong, waterproof bond between the solar panels and the camper van’s roof, we modified the bottoms of the Z-bracket feet first.
This is how we did it:
Step 1: Attach Z-Brackets To Solar Panels
Our first step was to affix our Z-brackets to our solar panels. This was a straightforward process because the panels already arrived with several prefabricated holes specific for fitting on Z-brackets.
The Z-brackets also come with all the hardware you need to affix them to the frame of the rigid solar panel.
Step 2: Attach VHB & Butyl Tape To Z-Bracket Feet
A bit of a crude Photoshop graphic, but this is an image of the underside of the Z-bracket foot. This is the side that will adhere directly onto the van’s roof.
What we did was place Butyl Tape around the prefabricated screw holes (grey area) on both ends of the Z-Bracket and place the 3M VHB Tape in the middle (red region)
This way, the butyl tape will act as a waterproof seal around the screw holes and the VHB tape in the middle will provide additional adherence while driving.
Step 3: Place Solar Panels On Camper Van Roof
After all of the undersides of the Z-brackets were prepared with VHB and Butyl Tape, it’s helpful to find 1-2 other strong people to help hoist the panels up onto the roof.
Because both the VHB and Butyl Tape are on the Z-brackets, you’ll want to place the solar panels in the exact spot you want them located on your camper van’s roof. Because once you place the panels down, it will be difficult and messy to re-locate them again.
Step 4: Drill Solar Panels To Camper Van Roof
This is easily the worst part of installing solar panels on the camper van’s roof. Drilling holes into our van’s roof really me a queasy stomach.
The Z-brackets, which we purchased on Amazon, came with self-tapping screws. This was convenient since it meant we didn’t have to do any pre-drilling.
When you drill the screws, through the Z-bracket, into the van’s roof, you’ll notice that the Butyl Tape compresses and begins to get squeezed out the sides of the Z-bracket feet. This is a good sign and should tell you that a water-tight seal is being formed around the screw hole.
Step 5: Cover Z-Brackets With Lap Sealant
Once the panels were screwed down, we extruded Dicor Lap Sealant all over the Z-brackets for an additional layer of water-proof protection. We really like this particular lap sealant because it’s quite liquid, which makes it easy to apply onto surfaces and easily smothers all the gaps and crevices to create a tight, waterproof seal.
Step 6: Let Everything Dry & Cure
As a last step, we covered our roof with a tarp for 48 hours to allow the VHB tape, Butyl Tape, and the Lap Sealant to fully cure.
How To Connect Solar Panels To A Camper Van Battery
Once your solar panels are connected to your camper van’s roof, the next step is to connect those solar panels to your camper van’s electrical system so that you can begin charging your house batteries from the sun.
The entire process is slightly more complicated than simply connecting the solar panels directly to your batteries, but it’s entirely doable.
Below we detail, step-by-step, how to connect your camper van solar panels to your batteries. We also provide an easy to understand wiring diagram that gets you from A to Z.
We relied on these three tools to connect our solar panels to our camper van’s electrical system.
From the solar panels the house batteries you will need to connect the following components.
Step 1: Connecting Solar Panels Together
If you have multiple solar panels on your van’s roof, you will first need to connect them together. Just like with batteries, you can connect the panels either in “series” or in “parallel”.
If the distance between your solar panels and charge controller will be longer than 20feet OR if your campervan batteries run on 24-volts, you may want to connect your panels in “series”.
But for the vast majority of people (including ourselves), we connected our solar panels in “parallel”. By connecting your panels in parallel, the total number of amps increases, which charges your house batteries faster.
Using Branch Connectors To Connect Solar Panels
To connect solar panels in parallel, connect all your panel’s negative (black) wires together and positive (red) wires together to form a single negative output line and a single positive output line. This is done with branch connectors.
In our case, because we have two solar panels on our camper van roof, we used “2-to-1” branch connectors to connect our two solar panels together. If you have three or four panels, you’ll need to pick up “3-to-1” or “4-to-1” branch connectors, respectively.
Step 2: Passing Solar Wires Through The Solar Entry Gland
After connecting both the positive & negative branch connectors to the solar panels, we now have a single positive (red) connection point and a single negative (black) connection point.
From here, we took our red and black 10awg wires and crimped on MC4 connectors onto each wire end (using our wire crimper and MC4 assembly tool). We then connected our “2-to-1” branch connectors to our 10 AWG wires.
It’s important to get a good quality crimp around the 10awg wires or else the wires might slip off due to the constant vibrations while driving.
We needed to pass these 10 AWG wires through our van’s roof and into our camper van. To achieve this, we passed the solar wires through a solar entry gland and then through a 1/2″ that we drilled through the van’s roof.
The solar entry gland was then sealed over the 1/2″ hole to prevent future water leaks.
Step 3: Connection To The Solar Charge Controller
Now that the positive & negative 10awg wires are inside the camper van, we ran both the red and black wires towards the location of our camper van’s electrical system.
We took our red 10awg wire and connected it to a 10amp in-line fuse to protect the downstream charge controller from electrical surges.
To do this, we simply attached a MC4 connector to the red wire end and connect it to the fuse.
After the 10amp fuse, the red wire goes directly into the Solar Charge Controller. In our Victron Solar Charge Controller, the correct input is marked as “PV +”
The black wire also goes directly into the charge controller marked as “PV -“
The purpose of the solar charge controller is to regulate the amount of current that is fed into the batteries. Without a charge controller, a solar panel can easily ‘over-feed’ a battery and destroy it.
We really like our Victron Solar Charge Controller because it is bluetooth enabled and you can download Victron’s smartphone app to help keep you on top of your daily solar energy harvesting.
Step 4: From the Solar Charge Controller To The Bus Bars
Coming out of the solar charge controller, we took our red 10 AWG wire and connected it to a 30amp circuit breaker.
Just like all our other breakers, this protects our system from unexpected electrical surges.
After the circuit breaker, we brought the red wire straight to the positive (red) bus bar. For this, we needed a 3/8″ ring connector made for 10 AWG wires. This ring connector will fit over the bus bar binding post.
For our black 10 AWG wire, we brought the wire out of the solar charge controller and connected it straight to the negative (black) bus bar.
The Final Result: Connecting Solar Panels To Camper Van Battery
And you’re all done! Because we connected our house batteries to the red & black bus bars (in a separate post), our solar panels are now ‘effectively’ connected to our batteries.
To learn more, read: How To Build A Camper Van Electrical System
Total Camper Van Solar Panel Installation Diagram
When you’re all finished, your camper van’s solar system should look something like the diagram below.
FAQ - Questions About Camper Van Solar Systems
Are Flexible Solar Panels Worth It For Stealth?
We thought long and hard about flexible panels. The thinner profile really appealed to us.
But we had major questions about their durability and tendencies for scratches to appear on the surface. In the end we went with the rigid panels
And we love our rigid solar panels. In the end, being a ‘stealthy campervan’ didn’t turn out to be as important as we thought. What is much more important is having strong, durable solar panels for our campervan that won’t fail us half-way through our journey.
Your Recommended Solar Charge Controller Is Quite Pricey (Victron), Is It Really Worth It?
We understand, if you have a tight budget purchasing premium items is, many times, out of the question. There are several other great quality MPPT Solar Charge Controllers that you can purchase out there that will get you the same result for less money.
If a Victron Solar Charge Controller is within your budget but you’re just questioning it’s value, then we can tell you that the Victron charge controllers are absolutely worth the extra investment.
The simple reason for this is because they are one of the only Bluetooth-enabled charge controllers on the market today. The Bluetooth feature pairs with Victron’s smartphone app and lets you monitor your solar status instantly on your smartphone. This has been invaluable when trying to monitor our battery’s state-of-charge (% charge) each day we’re on the road.
AGM or Lithium: Which Batteries Are Better For A Camper Van Solar System?
Both batteries work great! AGM + Solar is a successfully tried and tested paring. And we’ve been charging our lithium batteries with our panels for 2+ years with no problems.
It’s important to understand each battery’s charging preferences to maximize their lifespans.
We discuss how we do this in our article: Camper Van Battery Charging Tips
Solar Charge Controller: MPPT vs. PWM?
You may have noticed that PWM Charge Controllers tend to be cheaper than their MPPT counterparts.
This is because MPPT controllers are a newer technology and able to better harvest power from the sun. MPPTs are often 20-30% more efficient.
Because of this, we highly recommend the MPPT controller varieties. The amount of daily harvested solar power varies greatly and so maximizing the possible intake is crucial.
Final Thoughts: Solar Panels For Campervans & RVs
When we first began thinking of adding solar panels to our campervan, we thought it was an incredibly daunting task!
The difficult terminology, and so many different products and required connections. It was a bit overwhelming.
But step by step, we were able to build a robust solar power system that fits our campervan life needs and lifestyle. And if we can do it, we’re confident you can, too!
If you have any question, please let us know in the comments below or send us an email in the Contacts Page.